Examples of known catheters include, without limitation, flexible insertion tubes of endoscopes (including flexible insertion tubes of colonoscopes and enteroscopes). The insertion tube has an articulatable distal end portion controlled by wires running from the distal end portion to control knobs on the handle of the endoscope. A wide angle video camera in the distal end of the insertion tube permits medical observation. Medical devices, such as a medical needle-knife or a medical snare, are part of an endoscopic system and are insertable into the working channel(s) of the insertion tube of the endoscope and are translatable to extend from the distal end portion for medical treatment. In use, the distal end of the insertion tube is inserted into a body lumen of a patient. The user manually pushes on a proximal tube portion to advance the distal end of the insertion tube within the body lumen for medical observation and/or medical treatment. In a serpentine body lumen, such as the colon, the articulatable distal end of the insertion tube can become misaligned in the body lumen and become blocked by lumen tissue from further advancement. Then, if the user further pushes on the proximal tube portion, the insertion tube forms undesirable loops which the user must correct before realigning the distal end of the insertion tube and further advancing the insertion tube within the body lumen. U.S. Pat. No. 6,866,626 discloses performing a colonoscopy using a self-propelled capsule connected to the distal end of an umbilicus, wherein electrodes on the capsule stimulate muscular colon tissue to contract thereby advancing the capsule within the colon.
Still, scientists and engineers continue to seek improved medical instruments having a catheter and improved methods for using a catheter.